Shaking a symptom of ?

I had a 76 y/o patient yesterday who went down for a colonoscopy even though he had not been properly prepped. He had not had a stool in a week and the CT revealed a mass obstucting his colon. The doctor ordered tap water enemas before the colonoscopy just to prep what we could. The tech gave him a total of 6000cc of tap water enemas (actually an agency RN) with just clear return. No c/o's per patient re pain or anything.

He came back from the procedure and the doctor told me that he had a large mass that was CA and that the radiologist had told him that it was metastisized to the liver. Upon returning to the room he began vomitting fecal material (approx 750-1000cc), so as ordered I dropped an NG and immediately got a 600cc return of more fecal material. I left the suction on med/intermittant and shortly after lowered it to low/intermittant. About 2 hours later I was paged to his room. He was having the hard shakes and c/o being cold. His temp was 98.2 and all VS were normal. I put him on a dinemapp for Q 5 minutes and the VS and temp remained normal. I called the doctor who ordered a CBC and BMP. By the time I got back to the room a total of 15 minutes or so had gone by since he first started shaking. He was no longer shaking, VS still normal, he said he felt better but he looked awful, greyish.

It was 1945 and I went home so I don't know how the CBC and BMP turned out. I went to the night nurse and gave her a complete update on what had just happened. Any thoughts on what might have been going on with him? Anxiety r/t dx ? Internal bleeding r/t colonoscopy? Drop in potassium r/t suction? His CBC and BMP were normal that AM. The only abnormal he had was a BUN of 35. Creat was WNL.